Single-package power meter

Abstract

A single-package power meter is disclosed for measuring the power consumed by a load connected to an electrical conductor. The power meter is galvanically isolated from the electrical conductor through the use of magnetic sensors or through the combination of magnetic sensors and capacitors. Instantaneous power consumed at the load and other desired parameters are determined by measuring the voltage of the load and current flowing through the electrical conductor. Current is measured using a magnetic sensor to detect the magnetic field associated with the current flowing through the electrical conductor. Voltage is measured by one of two possible techniques involving magnetic sensors to measure the current flowing through a coil connected in parallel with a load, or through the use of a capacitively coupled voltage divider connected in parallel with the load. An application specific integrated circuit is further disclosed that controls the bias currents of the sensors for autoranging purposes and also for computing desired parameters, such as power consumption.